Optical fibers are becoming increasingly more prevalent as a medium for transmitting high bandwidth voice and data signals in telecommunications systems. There are a number of different standardized connectors in the fiber optic cable industry used for interconnecting two fiber optic cables to each other or for interconnecting a fiber optic cable to a piece of equipment. Some of the more common standardized connectors are the LC, ST, SC, and FC type connectors. Each of these types of connectors must meet certain dimensional standards. Also, typically, any type of connector system typically comprises two complementary connectors, e.g., a plug (the male connector) and an adapter (the female connector).
Unlike copper and other conductive media for transmitting electrical signals, fiber optic cable connectors must be designed so as to be extremely precise in terms of both aligning the optical fibers that terminate in the each of the mating connectors with each other and assuring that the ends of the fibers are clean and have as low reflectivity as reasonably possible in order to assure that the signals are effectively transferred from one fiber to the next with minimal loss of signal strength and signal quality. The connectors are made to precise tolerances and the process of terminating an optical fiber to an optical fiber connector, which process often is performed in the field, is laborious and painstaking.
Such fiber optic connectors may be disposed in environments that are harsh and in which dust, dirt, moisture, and/or other contaminants are prone to enter the connection. Generally, the aforementioned standardized connectors have fairly tight tolerances and do not permit the ingress of dirt or moisture under mild conditions, such as in homes and office buildings. However, in factories, motor vehicles, and outdoor settings, such as cellular antenna towers, in which moisture or dust may be significant, standard fiber optic connectors may not be adequate to prevent the ingress of dust or moisture into the connectors. When fiber optic connectors are expected to be located in such harsh environments, it is desirable to place a sealed housing around the connectors. Accordingly, protective enclosures are commonly used to prevent optical fiber connectors from contamination by dust, dirt, moisture, and other contaminants. Such protective enclosures also provide additional protection from mechanical damage as a result of the ruggedized housing and strain relief of the protective enclosure.
For instance, U.S. Pat. No. 6,227,717 discloses one exemplary protective enclosure for use with ST or SC type connectors.
Generally, a protective enclosure comprises two complementary mating halves just like the connectors themselves, namely, a plug half and an adapter half. Each of the halves typically mounts over the corresponding half of the connector and comprises some structure and mechanism for sealing the two connectors inside the structure with a relatively dirt and watertight seal. The Siemon Company of Watertown, Conn., USA manufacturers an industrial protective enclosure for a duplex LC type fiber optic connector. The plug half of the protective enclosure comprises an LC connector holder that includes two saddles within each of which an LC connector is slid sideways (i.e., transverse to the axial direction of the optical fibers). As the plugs are slid sideways into the holder, the installer must hold down the rear latches of the LC connectors so that they can slide under a bar on the holder that contacts and defeats the rear latches of the LC connectors, permanently holding them in an inwardly flexed position. Then, while manually holding the duplex LC connectors and LC connector holder together so that they do not fall apart, the installer slides this assembly axially into the plug protective housing while manually aligning the LC connector holder for proper placement in the housing.
With respect to the adapter half of the protective enclosure, the LC adapter is slid axially into the adapter half of the protective enclosure. The adapter half of the Siemon protective enclosure includes grooves for matingly engaging the latches that are on the side surfaces of LC adapters to lock the LC adapter within the adapter housing portion of the protective enclosure.
The two housing halves of the protective enclosure mate with each other via a conventional bayonet type mating, thereby sealing the LC adapter and plug within the protective enclosure.